package com.scy.edu.server;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

/**
 * @author 司晨雨
 * @date 2020/6/28 21:23
 * @description
 */
public class StaticResourceUtil {

    /***
     *获取静态资源文件的绝对路径
     * @param path
     * @return
     */
    public static String getAbsolutePath(String path){
        String absolutePth = StaticResourceUtil.class.getResource("/").getPath();
        path = absolutePth.replaceAll("\\\\", "/").replaceAll("%20", " ") + path;

        return path;
    }

    /**
     *读取静态资源文件输入流，通过输出流输出
     */
    public static void outputStaticResource(InputStream inputStream, OutputStream outputStream) throws IOException {
        int count = 0;

        while (count == 0){
            count = inputStream.available();
        }
        int resourceCSize = count;

        //输出http请求头,再输出具体内容
        outputStream.write(HttpProtocolUtil.getHttpHeader200(resourceCSize).getBytes());

        //读取内容输出
        long written = 0;//已经读取的内容

        int byteSize = 1024;//计划每次缓冲的长度

        byte[] bytes = new byte[byteSize];

        while (written < resourceCSize){
            if(written + byteSize > resourceCSize){//说明生育未读取大小不足一个1024长度，那就按真实长度处理
                byteSize = (int) (resourceCSize - written);//生育的文件内容长度
                bytes = new byte[byteSize];
            }

            inputStream.read(bytes);
            outputStream.write(bytes);

            outputStream.flush();
            written+=byteSize;
        }
    }




}
